making of wax-sheets, and the mode of impressing them, we will give directions for making a wax-sheet by a very simple method. Having obtained a plaster cast, trim it until it is a little smaller than the inside of the frame, so that the frame may be easily slipped round it; next obtain a zinc train, a little larger than the cast, and in. deep. Place the tray and cast on a piece of board, and placing a frame over the whole, measure how far the centre of the bar is below the top of the cast, and then prepare a few slips of wood of just such a thickness which will, when inserted under the frame-one under each side-and fastened to the board with a few sprigs, raise the centre of the frame to the level of the surface of the cast. Having poured a little water into the tray, and sprinkled the cast liberally until the surface is wet-but no water visible in the hollows-a quantity of melted wax is dabbed all over with a common bog-hair paint brush until the whole of the surface of the cast is covered. With a camelhair brush the wax is dabbed close up to the top bar, so as to fasten the sheet to the bar securely, but the sides and bottom are left free. Care must be taken to do this latter part neatly, so as not to daub the whole of the undersides of the top bar, as the bees greatly prefer the top of the sheet to be level and regular. When the operation is complete the bar must be carefully lifted, and a wax sheet will be fixed inside the frame, bearing the impression of the cell bottoms all over its surface, and if the whole be placed inside a hive containing a new swarm, the bees will, in a few hours, excavate the cell bottoms to their normal thickness, using the WALI removed to form the cell walls, and conTert the sheet into a beautiful white comb, in which the queen will begin to deposit her eggs before the cell walls are raised to their full height. If every bar in a hive is treated in the way described, the bees will convert the sheets into combe in one quarter the time they would take to build them, and--here we have the great advantage of impressed sheets-as the bee master has laid the foundation of each cell at the same time as he supplied the material, the bees are compelled to build worker combs, and the suitability of such a swarm for saving a stock is to a great extent insured. Although the novice must expect to fail in his first attempt at painting the wax on the cast evenly, a very few trials will enable him to perform the operation in a satisfactory manner, and the little trouble he has been at in preparing his casts, &c., will give a greater zest to his pursuit, and give him a thousand times more pleasure than the rich amateur can ever feel who purchases the whole of the little necessities "ready for use" as they reach his hand.

To be able to stand before a hive and say, "Alone I did it," is a far prouder position than to exhibit a score of hives which have had more attention from a menial than from one's Belf, and which have probably cost twice the money they will ever return.

Should it, however, be difficult to obtain a comb suited to the purpose of division just described, a cast may be purchased for about half a crown suited to a hive which has the Woodbury bar or a little larger.

In our next paper we shall explain the mode of manufacturing the sheets of wax, and also a ethod that has just been introduced which promises to surpass all other plans of "embossing," W. S. Travis.

DRILLING SQUARE HOLES.

from one of the outer corners to the centre of The patentee prefers to make the guide bar
the triangle. The proposed method of using of steel, which he hardens at that part where
such drills in an ordinary vertical drilling the guide hole is made. The method of opera-
machine is as follows:-A special drill chuck, tion is then as follows:-The three-sided drill
forming part of the invention, is provided, and being fixed in the self-adjusting chuck, the
attached to the lower end of the drilling guide bar with the square guide hole therein
spindle. The chuck is constructed in such rigidly fixed above the point where it is re-
manner as to admit of the drill travelling auto-quired to drill, the drilling spindle carrying
matically in a horizontal plane some little dis- the chuck drill is made to revolve, and is
tance. This is rendered necessary by the screwed or pressed downwards, upon which the
peculiar movement of the cutting edges of the drill works downwards through the square
drill, which does not operate or rotate on a guide hole, and drills holes similar in size and
fixed central point, but diverges somewhat in form to that in the guide. The triangular
proportion to the size of the hole.
drill for drilling dead square holes may also be
The drill chuck is constructed in the follow-used without the self-adjusting drill chuck in
ing manner:-The upper part of the cavity of any ordinary chuck, when the substance ope-
a metal cylinder is bored out circularly, so as rated upon is not very heavy nor stationary;
to fit on to the drilling spindle, to which it is then, instead of the lateral movement of the
screwed by one or more screws. Below the drill, such lateral movement will be commu-
circular bore a square recess is made, and below nicated by the drill to the substance operated
this latter, and coming well within the limits upon.
of the square recess, there is a circular hole
passing through the end of the cylinder. The
drill-holder or socket is in a separate piece,
the bottom portion of which is provided with
a square or round recess for holding the shanks
or upper end of the drill, which is held firmly
in its place by means of a set screw. The
upper part consists, first, of a screw, S, at the
top, Fig. 1; secondly, of a square shoulder, B;
thirdly, of a circular shoulder, D; and, fourthly,

of another but much larger circular shoulder, E. Through the circular hole at the bottom of the hollow cylinder the upper portion of the drill-holder is inserted until the large circular shoulder meets the bottom of such cylinder. A loose square collar, A (Figs. 1 and 2), provided with an oblong rectangular slot, is then placed within the cylinder and over the square above mentioned, above and on to which is screwed down a nut, N, from the inside of the cylinder. The loose square is of such thickness that when the nut is tightened down on to the square shoulder the loose collar is left to work freely. When this is done the drill-holder will readily travel in a horizontal plane such disTo drill a square hole with a rotary motion tance as the play between two of the sides of at one operation may seem to many a the loose collar, and two of the sides of the novelty in mechanics, but Mr. J. Hall, of square recess, in one direction, and in another Chancery-lane, has obtained a patent for a direction the distance that the play between method of accomplishing the feat. His inven- two of the sides of the small square shoulder tion, he tells us, relates to the drilling of "dead of the drill-holder and the ends of the rectansquare holes, square holes, or modifications of gular slot in the loose collar. The horizontal the same," in metals or other substances, by travel or play is proportionate to the size of rotary motion at one operation, thereby super- the hole to be drilled. Near to the lower end eding the present method of making such or cutting edges of the drill is fixed rigidly a circular holes, then cutting or filing them until provided with a square hole similar to the hole boles, which is usually done by first drilling out metal guide bar or plate, F. The guide bar is they assume a square form. For this purpose it is required to drill, the dimensions of the e employs a three-sided drill, either flat or three sides of the drill being such that the disuted, which, in cross section, is of the form of tance from the base to the apex of the triangle, equilateral triangle. He makes the bottom which such three sides form, is the same as of rong edges of the drill perfectly flat, and the sides of the square hole it is required to ree in number, each cutting edge extending drill.

Although the patentee only cites the case of a vertical drilling machine in connection with this invention, he declares that the specified improvements are equally applicable to lathe, ordinary braces, ratchet braces, and all other descriptions of drilling apparatus. In making oblong dead square cornered holes, either the substance to be operated upon must be allowed to move in one direction more than another, or the hole in the guide plate must be made to the shape required, and the drill chuck made to give the drill greater play in one direction. Fig. 1 shows a vertical section of the improved chuck, in which A is the hollow cylinder, which may be attached to any ordinary drilling machine; H is the drill holder; S is a screw; B is a square shoulder; D is a circular shoulder; E is a circular shoulder of a larger dimension; N is a screw nut for tightening on to the square shoulder B, and the loose square collar. Fig. 2 is a plan view of Fig. 1. Fig. 3 is an elevation of the improved chuck; C showing the threesided drill and the guide-bar, F, complete. Fig. 4 is a plan of the guide bar, F, showing the three-sided drill in cross section.

THE ORGAN: A COMPREHENSIVE
TREATISE ON ITS MANUFACTURE,
PROCURAL, AND LODGMENT.*

BY JOHN WATSON WARMAN,
Associate of the College of Organists, London.
PART I. GENERAL TREATMENT IN
MANUFACTURE.

i. (d) IT will be obvious that small Pedales can be as effectively treated in foregoing method as larger ones (only that a still more effective course here is to use both Super and Sub-octave Couplers; this will be gone into before concluding). With regard to present Method, it will be sufficient to instance Ped. composed of Sub-Bourdon (32ft.) and Super-octave Coup.: or Sub-Bourdon (32) and Open Diap. (16) and Ditto: or Sub-Bourdon and Violone (16) and Do: or Sub. Bourdon and Flute (8) and Do: or combinations of these. Of course, the same care is here taken to avoid repetitions as in larger Pedales, such care being always obligatory with Octave Couplers, at all events, on Pedale. In Pedales of this size it is not necessary that either of the two 32's (more would of course directly make it a large Pedale) go below G, but no 32 must ever stop short of that note.

j. It will be seen that here there will be a still stronger reason for always taking the Vocal Bass on the Pedals exactly as it stands,

viz., that the portion of the latter corresponding with the said range-G to C-is now the finest : yet the seven bottom Ped. keys will be quite fine enough for the comparatively rare occasions on which they will be used, and the same may be said of the Ped. keys above the top C.

laid down in the two previous can be done as k. (e) It will be manifest that everything 32ft. Stop or Stops go right through or not. If easily with a Sub instead of a Super-Octave coupler, the guiding rule must be whether the they, or only one of them does, it will be better to use Super-octave, as that can run out at top C, and thus only two octaves of Action in the Coupler: but if no 32 below GGG, use Sub

*All rights reserved.

0.0. Now, it is obvious that this must be a very effective arrangement-first, it simplifies manipulation: second, it facilitates do., as the 4ft. cannot be on without 8ft., nor 32ft. without I have assumed through all these Pedale Jott: third, it gives four effective Stops: arrangements that its Clavier compass is only fourth, the breaks are veiled so as to become up to D, two and second octaves. But this is amat imperceptible: thus, with reference of course optional. to bottom break, it is confined to the 32, and z. As a summary of the two Species of Sup. veiled at least and inevitably by the continuity and Sub Borrowing it may be laid down thus: of the 16, also often of the 8, and yet again by The Ordinary gives most power for money; the 4ft.; as regards top break at C, it is being, in fact, the very utmost extent to which inevitably veiled by the 8ft., and practically Borrowing can be legitimately pushed. All the certain to be by the 16ft. also, for that is sure scheme (u, ante) really contains is 5 Stops, 2 of to be out: fifth, it necessitates fewer Pipes them extending only two octaves and a fifth, than the usual arrangement of Super and and the remaining 3 three octaves. The Action Sub octaves, for each extension includes only is not a formidable affair, with proper Kerbone half the Htops (this is, of course, balanced by the less power total): sixth, there is no abruptness in the additions, the Coupler never doubling what is already on, unless but one Stop be drawn (on Ped.),

p. The advantages of Ordinary Super and Bubort, Horrowing may be compared thus:-1, One Pallet throughout suffices. 2. One Pallet may use the other. 3. More power is obtained, each stop becoming really three.

q. The advantage of Divided up, and SubBorrowing are these: la. There are fewer Pipes. 20. Brenks are well veiled. 3a. Acces slims of power are more gradual. 4a. More variety is obtained.

r. No. 1 does not amount to much either way, for Large Pedales must have two Pallets to a note, and small ones derive great benefit from two distinct pressures (ace 10, e). It must be remembered that two grooves are not involved, unless space cannot be allowed for two Front boards, and that latter are necessary in either eman with two prossures. No. 2 lose all value directly two promatres aro used, na then ne Pallet can only nasist the other, so far an

Platform (see Depart. of PLATFORM), and the practicable Pedale is 15 Sounding Stops. At the same time the breaks will be palpable, though not offensive, the amount of the cessation vary. ing from one-half to one-third of what is actually sounding.

[28. a.] The Divided arrangement may be considered, on the whole, decidedly the more artistic one; at the same time it is of course not so strikingly economical. Thus, the scheme (w, ante) really contains 7 Stops, and its practicable size is 14-that is, the number is only doubled instead of trebled by the two Couplers. On the other hand, the breaks are almost impalpable, and the Pipes are considerably fewer, for it is only at one end that each has to run beyond the Clavier. The additional expense of Pallets and grooves can hardly in fairness be reckoned, for two grooves are only necessary when space cannot be spared for two Front boards, and the two Pallets will be very desirable with so large a Pedale in either of these arrangements.

b. There can thus be little doubt that except whore funds are very limited the Ordi

In

WATER-TUBE BOILERS.*

drawn alone it can sound the whole of the
Bourdons, but none of the Open Pipes.
former case the wind coming from the Open-Tongst engineers and steam users, that the
HERE is an impression, more or less vague
pipe side opens the Valves leading to the marine and stationary boilers of the future will be
bottom octave of the Bourdon; but at same found in some modification of the water tube type.
time shuts the valve leading through to Should the difficulties of lubrication and leakage be
Treble of latter. In second case, the wind overcome, and steam of over 300lb. pressure come
coming from Bourdon Treble opens the Valve into general use, then the employment of a boiler
between latter and its Bass; but blows against of small section will become in some measure a
-and thus closes-those leading from Bourdon necessity. But as long as the pressure does not
much exceed 150lb. there can be no actual necessity
Bass to the department of the Open 16ft.
for departing from the present practice of using
boilers of large section.

For this latter very ingenious arrangement I am indebted to Mr. Gern, of Boundary-road, Notting-bill. The treatment has been by him adopted at St. James', Norlands, London.

j. j. It is now necessary to observe that the foregoing with reference to Borrowing on Pedale (commencing at 26, z.) has been gone into so fully in order to indicate the best methods of treatment without too much departing from what is at present usual. But, as will be seen in COUPLERS (149, y, and on) and SPECIFICATIONS (own Dep.), the most effective and economical treatment of the Pedale is by Part or Divided Coupler Arrangement (chiefly by Sub.), described at n. ante and on.

heating surface is not mainly vertical, the steam can escape only by means of a column or system of past the heating surface and carry the rising columns of water being set in motion which sweep particles of steam along with them. In boilers with vertical water tubes of, say, less than 5in. diameter, the escape of the steam is mainly due to the same action. Now as the ascent of the lighter column is an effect and not a cause of the descent of the heavier column, it stands to reason that the first point to be considered in designing a water-tube boiler is to provide for this downward motion, and this is just the point that is in most cases either insufficiently considered or altogether ignored. De-signers of water-tube boilers appear to be so greedy. of heating surface, and bent upon getting as many places as possible for the water to rise from, that they forget to provide means for the colder water to get down, which it must do to cause the hot water to rise. The same strictures apply to boilers of other design where sufficient facilities are not provided for the water to descend.

It has sometimes occurred to us that the generally inaccurate way of expressing ideas of the phenomena of ascending bodies is accountable for much that is defective in boiler design. It is said that a portion, of heated liquid or fluid rises in the cooler mass surrounding it because it is lighter. We might just as well say an empty scale rises because it is lighter, when it is lifted by the weighted scale descending at the other end of the beam. As long as we have to refer the rising of the heated particles of a liquid to gravitation, whether we so speak of it or not, we. should keep the actual cause before us, and so design our boilers as to admit of the full and unimpeded exercise of gravitation taking place to bring about the end in view.

The preference that has hitherto been shown in many cases for boilers of small section to work at what cannot be called extraordinary pressures must be due to their possessing some real or imaginary advantage over boilers of large section. These advantages can, generally speaking, be only safety and economy of working. As to their safety it would not be difficult to make out a very strong case against what is claimed for these boilers-viz., that in the event of an explosion there is no danger to life or property. A few years ago one well-known make of water-tube boilers became quite notorious for the number of lives it had destroyed. Comparing the number of persons killed by explosions with the number of boilers in use, it was found that this water-tube boiler was more dangerous to work than any of the boilers of large section in general use. The great majority of people killed by boiler explosions die actually from scalding, and in a crowded stoke-hole or close boiler-house the bursting of a 6in. or 8in. water-tube may prove quite as disastrous k. Hitherto we have spoken chiefly of Borrow-to life as the collapse of a flue tube or the giving way ings from one part of a Soundboard to another of a shell plate in a large boiler. Several 8in. tubes of same. It is now as well to say a little more that have given way have been rent for a length We have heard more than one distinguished about borrowing from one Clavier to another. over 20in., and opening out nearly flat have pre-engineer say they do not believe in circulation at all It must be understood that although such sented two clear spaces Sin. in diameter for the in a boiler. But until these gentlemen can explain steam at a high pressure to issue from. A much how the steam is found at the top and the water at Borrowing is very strongly discountenanced by less opening than this taking place suddenly in a the bottom of a boiler, with passages more or less author, yet he does not wish to be dogmatic on boiler at work is sufficient to insure the death of all tortuous, we shall maintain that all water-tube the treatment; and it must be remembered that present in the stoke-hole. boilers should consist of separate downcast and upin one respect it is always easier than on same cast passages, in order that they may work well Soundboard-viz., that there is of course no under all conditions of firing. skewing of the Action or Groove-that is to say, not inevitably so.

For an excellent Instance of Ped. Sub-octave with one Stop see COUPLERS (150, a).

* FROM ONE CLAVIER TO ANOTHER.

(To be continued)

As for the economy claimed for water-tube boilers, apart from that due to the judicious use in the cylinder of steam at high pressure, it remains to be shown that these boilers can be more economical

In more than one make of water-tube boiler the same passages are used for the ascending and generators than stationary, marine, and locomotive descending currents. As long as the motion of these boilers of the ordinary types. In fact, some of the is regular and the passages are not too small the water-tube boilers we are acquainted with are any-action of the two currents can go on satisfactorily thing but economical generators when evaporating as much water as boilers that are much less troublesome to manage.

BALSAM MOUNTS.* THE condition of several balsam mounts which I There are some dozen different designs of waterhave seen lately induces me to offer some tube boilers, of which considerable numbers have suggestions for their better preparation. Balsam mounts are regarded as the most permanent dozen that have given very general satisfaction after been made, and we could enumerate at least half a of all, but are liable to changes caused by evapora-working some time in mills and works of various tion of the more volatile portions of the balsam. kinds. Yet when these boilers have been tried at This produces a vacuum, and the air forces its way in, in the form of bubbles, cracks, &c., and finally sea most of them have not survived a week's trial the balsam becomes so dry and brittle that a slight before they have been given up as hopeless. blow or shock will cause the cover to fly off. As I

side by side. The higher the pressure and the slower the action the smaller the passage necessary for the successful evaporation of a given weight of steam As the downward current is liable to be interrupted by the expansion of the rising steam on a sudden the success of any such arrangement will depend reduction of pressure at the surface, it follows that greatly upon the relative capacity of the steam space and the amount of steam drawn off at each stroke of the engine, and also, of course, upon the pressure at

which the boiler is worked.

write, I have before me a box of six slides belonging to the American Micro-Postal Cabinet Club, and of these four are more or less affected, from a few out what appears to us the reason why so many posing the two currents to pass each other on opposite bubbles just at the edge of the cover to the invasion of more than half of the area of the cover. Besides looking badly, their value is decidedly impaired. The remaining two are as neat and perfect as the day they were finished, and are good for an indefinite period yet. I have adopted a similar plan of finish. ing for some time, and find it requires no great outlay of time or labour. I clean away all the balsam

6

As most water-tube boilers are proprietary inSupposing the downward current in a vertical ventions, we desire to avoid undertaking the invidious task of comparing their relative merits passage to take place in the centre, and the upward and defects. At the sanie time we wish to point current to take place at the circumference, or sup tubulous boilers that have answered so well on land sides of the tube, the efficiency of the circulation at have leaked, rent, and proved such utter failures at any given pressure will depend greatly upon the of the tubes have been due to defective circulation. densities of the two currents. By increasing the sea. In nearly every case the leakage and rending relative temperatures, and consequently relative, As this has so often been said before, and apparently temperature and reducing the density of the upward so little endeavour has been made to remove the current the space for the downward current will be defect we refer te, it may be assumed that designers, reduced. If the velocity of the downward current as a rule, have ignored its importance. We have increased as the space allotted to it decreases, the which exudes when the cover is pressed into place, found that engineers are frequently too apt to use efficiency of the circulation would still be maintained; except enough to fill the angle formed by the edge of the expression defective circulation" as they do but this is not so, as the resistance due to friction. the cover and shde, and present a sloping surface. unequal expansion and contraction," and "gal- increases very rapidly with any tendency to increase When this hardens, I put the slide on my turn table, vanic action," without having a clear notion of the the velocity. It follows, then, that with a given size and run a ring of gold size around the edge of the actions these expressions are meant to describe. of vertical passage an increase of temperature be cover, of course having taken the precaution to We purpose, therefore, pointing out how the de-yond a certain point will diminish the efficiency of "centre" the object when first mounted. The object fective circulation in water-tube boilers has been the circulation, and consequently the safety, durain using gold size is that if admixture between it the cause of their failure at sea, as the question of bility, and efficiency of the boiler. Now we consider and the balsam takes place to discolouration using water tube boilers has assumed some impor- this to be the cause of the failure at sea of so many results, but asphalte and white zine will mingle and tance since their trial in the Royal Navy has been water-tube boilers that have worked well on land. spoil the mount. After the gold size hardens, the ring may be fai-hed as fancy dictates. I sometimes so strongly recommended by the Admiralty Boiler With a combustion of 10lb. or 121b. of coal per square foot of grate per hour a boiler may give put on a ring of white zinc, and run on a delicate excellent results that will be a complete failure with a combustion of from 201b. to 30lb. Here we have large section and most water-tube boilers that have one very important difference between boilers of elasticity in the rate of combustion as the former. been tried at sea. The latter admit of no such easy, and the water is merely simmering, almost any sort of an arrange As long as the firing ment will do for a boiler, if it will only bear the pressure, but for heavy firing and fierce ebullition something more is required. We must either have our engines and condensers in such order, and our boilers with such a margin of power, that no demand for steam that can arise will necessitate such an

ring of some bright colour at the outer and inner

edge of the white zinc.

If despatch is required, bleached shellac dissolved in alcohol may be used for the first ring, as seen as the colour adheres enough to bear the slight touch of the brush, and then finish as before.

The time expended is amply repaid by the improved appearance of one's cabinet, and durability secured. The Postal Club slides are not the only ones which suffer, for I have in my cabinet some not put up over two years, which were decidedly injured by evaporation. I remedy the trouble by dropping tarpentine to the edge of the cover. is soon is

Committee.

In designing boilers, both of large and small section, the aim has generally been to get as much assumed that the heated water and steam will beating surface as possible into a given space. It is vertical or horizontal. Sometimes the facilities for ascend from the heating surface, whether this be the steam are considered, but it is very rarely that the rising of the heated water and for the escape of the facility for the descent of the colder water to displace the heated water is taken into consideration and provided for. In the great majority of cases the fact is altogether overlooked that the heated particles of gases and water must either rise like so many corks in the body of the water through

drawn in, and when the holes are all filled I put some being displaced by the denser water surrounding increase in the rate of combustion as to interfere fresh in Or we must evaporation takes place again, it flows in and fills up the old air spaces. By this means and a little patience, I have saved several valuable slides.

By F., HAMLIN, D., in the American Journal of Microscopy.

lighter column displaced by one of greater density.
In multitubular boilers of large section the circula-
tion in either of these ways can go on more or less
unimpeded. In all water-tube boilers where the

* From Engineering.

make our boilers in such a manner that any increase in the rate of combustion will increase the rapidity of the circulation, and rather promote the efficiency of the boiler thau diminish it. That most of the water-tube boilers that have been tried at sea have not been so made has been shown by the manser ir,

MUSHROOM CULTURE IN FRANCE.* Mo USHROOMS are decidedly better done in France than in England. Possibly part of the undoubted superiority of French mushrooms may arise from the places where the major part of them are grown, that is, in underground caves, ranging from 20 to 100 feet in depth from the surface. Few English cultivators who have had the opportunity of growing mushrooms in cellars but must have been struck with the superiority of the produce and the greater ease and certainty with which they are grown in such positions, provided always, however, that the cellars are neither too cold nor too damp. The great advantage of cave or cellar culture is the uniformity of heat and of moisture under such circumstances. All sudden or severe changes in the temperature or hygrometrical conditions of the air are unfavourable or fatal to the healthy life and growth of such funguses as the edible mushroom. So much is this the case that mushrooms in the open air come and go, as every observer knows, with almost any and every change of atmospheric condition. Now the deeper the cave the more steady are these two important factors in mushroom-growing heat and moisture. The caves may be said to provide the external conditions of mushroom culture in the best and most steady state for the purpose-the temperature from 60° to 66°; the air in that medium state in regard to moisture most congenial to the beds from being quickly or at all dried beyond what growth of the mushroom, protects the uncovered is favourable to the mushroom. This last is of great importance, for many years' experience convinces me that the less mushroom beds are watered the better. Each watering involves serious risks: it may stimulate the bed to renewed production, it may also ruin it, and often does. Now the French water their beds at times, but the place as well as the mode of culture reduces the amount of water, and also the risks involved in giving it to a minimum. This will appear as we proceed, but given a place to grow mushrooms that reduces the water needed to the lowest limit, and you furnish the cultivator with But the whole of the superior success of the French in mushroom culture must by no means be attributed to their subterranean advantages, for many of the French mushrooms are grown in sheds, stables, houses, or cellars, or in the open air as in England. While, therefore, in the caves, culture may be more certain and easy than in other places, the French growers are successful anywhere. For example, few places could have furnished more unfavourable external conditions than the central table of the borticultural annexe of the Paris Exposition. Yet even there, among other exhibits, where the air was so hot and dry that flowers had a struggle for existence, the model mushroom has continued studded with white buttons and charming clusters of temptinglooking mushrooms. French mushroom culture differs from ours chiefly in the character or quality of the materials employed-in the size and form of the beds-in the mode and time of gathering, and after and general treatment of the same.

three out of four of his chances of success.

doubtless favours this rapid succession from every bearing centre. Each hole made by the removal of a single or a cluster of mushrooms is at once filled up with a handful of soil, which is pressed in firmly and watered if necessary. Fresh mushrooms appear in an incredibly short time from their old centres, and in this way the tiny beds are kept in full bearing for a couple of months or more. Large mushrooms are entirely unknown in France, at least I saw none, and know that many French cooks will have none of them in England; and there can be no doubt that in the eating of mushrooms the French are as much in advance of us as in their cultivation, and the latter seems about as perfect as may be. The labour, skill, and capital devoted to mushroom culture around Paris are enormous, and the quantity grown for home consumption and exportation, especially to England, very large; yet the leading champig nonistes do not strike strangers as rich, while the men employed among the beds seem to have to struggle rather hard for a living as well as for mushrooms. It is the old, old story over again-large returns and large expenses, leaving after all a comparatively small margin for profits between the two.

beds or beds in full bearing; in fact it is that, though
it is sold under the names 66
virgin" and made'
spawn-the difference being that the virgin spawn
is made by accident and the ether by design-the
first is found mostly in heaps of manure, the second
is manufactured in beds prepared in all respects like
those for mushrooms. As soon, however, or rather
just before the mushrooms appear, the bed is broken
up, and the spawn-that is, all the manure or sub-
stance of the bed permeated by spawn-is used for
the spawning of other beds, or stored away in a dry,
cool place for future use. The first impression of
an Englishman on handling French spawn is, that
the mycelium has run too far. We are familiar with
that state in our brick spawn; and as the French
spawn is almost white with the threads of musb-
rooms, we naturally come to the same conclusion in
regard to it. This is a mistake, however. Experience
of its use enables me to state that it is excellent in
quality, and under identically the same conditions
produces mushrooms in great abundance and of
excellent quality about a fortnight sooner than good
English spawn-that is, in a month from the time of
setting. It seems also to be equally durable, and
fills the bed more full of spawn than the English.
The carriage and cost of manure and produce-
The French, however, seldom use spawn from old the price of labour, risk of failure and of lo38-eat
beds.
splendid crops may often be raised from such spawn, fortunes being made out of mushrooms alike in
In this no doubt they are wise, for though deeply into the profits. Still we have heard of
there is the risk of failure from its over-development France and England; and in few pursuits could
before planting-a point difficult to explain in words success be better merited or more useful to the com-
but so familiar to practical cultivators that most of munity at large.
For mushrooms manufacture
us could probably pick out bricks or flakes of spawn wholesome food out of their waste, and leave the
that had been pushed beyond the limits of mushroom waste almost as valuable for the land as they found
growing by over-heat or over-time in the manu-it. In France the value of spent mushroom dung as
facture. The great art in the making of French and a feeding surface muleh is as widely known and as
English spawn is to arrest the running process at highly appreciated as in England.
the right moment. Under-development and over-
development of the mycelium equally renders the
spawn worthless. The soil used to cover the beds is
Most of the mushrooms sold in the Parisian markets
also different, and far less of it is used. Pure sand
or white sandy gritty soil is that generally employed.
bear traces of the covering soil on their crowns, and
some of them sparkle like globes of spar from the
But no particular soil is used-anything available on
sharp pieces of freestone or silica on their crowns.
the spot seems employed for a covering of an inch or
two, seldom so much as two. The mode of soiling
is similar to that employed by most English growers.
together and left for a few days or a week to prove
The materials of the beds are pressed pretty firmly
the heat. Should that not exceed 70° to 75° the bed
is spawned, the spawn being inserted in flaky pieces,
larger than those used in England, and at distances
of from 8 inches to 1 foot or 15 inches apart, and 1
or 1 inch deep. After spawning the bed is pressed
firmly down and left unsoiled to see if the spawn will
cold sheds or places in cold weather, the whole is
run, and in the case of out-of-door beds or those in
covered over with litter to accelerate the development
of the spawn. In a week or so, when it shows itself
running through the mass of the bed, the litter is
covered with soil or sand to 1 or 14 inch in depth,
and in caves, &c., no other covering is ever applied
to the surface of the beds. The French also prefer
perfect darkness to light, and are careful to avoid
draughts or currents of cold air.

THE BUZZING OF INSECTS.

T buzzing of insects was produced by the vibra HE old naturalists thought generally that the tions of the wing, but they had scarcely attempted to analyse this phenomenon, and their opinion was wings are cut a blow-fly continues to buzz. Other abandoned when Reaumur showed that when the explanations of the phenomenon have been advanced by various naturalists, but none of them are satisfactory. M. Jousset de Bellesme has been making that previous theories are unsatisfactory, he de some investigations on the subject, and, after proving scribes the results of his own researches. To avoid confusion it should be distinctly understood what is meant by buzzing. In the scientific acceptation it

means to imitate the sound of the humble bee, which

is the type of buzzing insects. But the humble bee gives out two very different sounds, which are an and a sharp sound when it alights. We say, then, octave of each other-a grave sound when it flies, that buzzing is the faculty of insects to produce two sounds at an octave. This definition limits the phenomenon to the hymenoptera and the dipters. The coleoptera often produce in flying a grave and dull sound, but they are powerless to emit the sharp sound, and consequently do not buzz. There are two or three ascertained facts which will serve as guides in the interpretation of the phenomenon. The beds generally are very small and of ridge First, it is indisputable that the grave sound always forms, seldom exceeding in breadth or height 2 feet, accompanies the great vibrations of the wings, many of them not being more than 4 inches in height which serve for the translation of the insect. It is and breadth of base. Possibly these sizes are main- easily seen that this sound commences as 2003 as tained partly by the force of habit, though this the wings begiu to move, and that if the wings be breaking up of the somewhat volatile material of cut off it disappears entirely. The sharp sound is which the beds are formed may tend to give it never, on the contrary, produced during flight; it is Of course horse manure, spawn, soil, are the bases greater stability, and assuredly protect the ferment- only observed apart from the great vibrations of the of mushroom culture in France as in England; yet ing manure from most of the risks of over-heating. wings when the insect alights, or when it is held so from the very first the practice varies. In England On examining the materials of several mushroom as to hinder its movement, and in that case the wing droppings alone are often desiderated, and these beds in bearing the greater freshness and roughness is seen to be animated by a rapid trembling. It is from special animals, the higher fed the better. In of the bed material were the most striking, charac- also produced when the wings are entirely taken France the entire litter from the stables seems used, terising all of them. The ridge form is also retained, away. From these two remarks we may draw the without any selection further than the careful rejec though it is difficult to perceive any advantages from conclusion that the grave sound belongs properly to tion of any foreign matter-that is, neither hay, straw, such steep ridges as distinguished most of the French the wings, that it is caused by their movements of or manure. Then in England it is customary to beds. The surface was much looser than that of great amplitude. There is here no difficulty. As throw the droppings into ridges to sweat out some most English mushroom beds. Judged by results, to the sharp sound it is certainly not produced by of the more gross elements or gases, and sweet n the however, and the closely packed way in which most the wings, since it survives the absence of these. mass; in France the litter is generally laid on the of the beds were furnished with excellent mush-Yet the wings participate in it and undergo a parflat, about 3 or 4 feet in thickness. Many English rooms, the form and sizes of the beds must be pro- ticular trembling during the production of this growers avoid as they would the plague the applica-nounced perfect. The modes and time of gathering sound. To discover the cause it is necessary to go tion of water in these preliminary processes; the are not those generally adopted in England, though back to the mechanism of the movement of the French make no scruple in freely watering any dry not a few English growers gather their mushrooms wing. It is known that among nearly all insects litter several times or at each turning. The greater length and porosity of their material may render this necessary. We mostly lay the manure up lightly to heat, they generally trample it down as firmly as possible. English mushroom dung in its preparatory stages is turned over and over on every second or third day for a fortnight. The French generally leave it for a week or ten days, and seldom turn it more than two or three times at such long intervals. The manure is consequently for rougher and longer than that generally employed in England. Hard spawn in the form of bricks is also unknown in France. The spawn is exactly like the flaky pieces of white manure, full of mycelium, with which mushroom growers in both countries are familiar, in old

From an article by Mr. D. T. FISH in the Gardeners' Chronicle.

in masses-considering all old stems poison to
succeeding crops-and also gather the buttons as
young as the French growers. The mushrooms are
turned out by the roots, so that there seems a con-
siderable sacrifice at first sight in this mode of taking
the crop experience, however, teaches us that the
sacrifice is more apparent than real, for it is seldom
that successional mushrooms in a group do much
good after a few are cut from it; and besides the
broader pieces of spawn used and its different
character spread the mushroom wider over the beds
than the English spawn, which masses them more
into dense clusters. By gathering the mushroom
younger, too, the beds bear more freely in succession;
so much is this the case that most of the French
beds are picked over every day or every second day.
The special system of top-dressing in detail every
place from which (mushrooms have been gathered

the muscles which serve for flight are not inserted in the wing itself, but in the parts of the thorax which support it, and that it is the movement of those which acts on the wing and makes it vibrate. The form of the thorax changes with each movement of the wing under the influence of the contraction of the thoracic muscles. The muscular masses iutended for flight being very powerful, this vibratory movement of the thorax is very intense, as may be proved by holding one of these insects between the fingers. But as the vibrations are repeated two or three hundred times per second, they give rise to a musical sound, which is the sharp note. In fact the air which surrounds the thorax is set in vibration by that directly, and without the wing taking part in it. There are then two simultaneous sounds, one produced by the vibration of the wings, and the other by the thoracic vibration, the latter twice as

rapid as the former, and therefore an octave. This is why in flight only a single grave sound is heard. When the thorax moves alone a sharp sound is produced. This, M. de Bellesme believes, is the only explanation that can be given of the mode of prodaction of the two sounds which constitute buzzing.

THE LATHE PLANING-MACHINE-
AMATEUR'S UNIVERSAL LATHE.*
N°
can uraight sliding
O amateur's lathe can be styled universal with-
surfaces form part of so many of his appliances, that
when he schemes-and what real amateur does not?-
he finds that without some means of forming a
straight flat face, or of making sliding V.'s, his lathe
is only half a tool, and amateur's tool-makers, to
upply this want, seem to have vied with each other
to bring forward not the most simple and practical
but the most expensive article. I trust, however,
if any of your readers try this, that they will find it
easily and cheaply made-very efficient, remarkably
easy to drive-little time lost in fixing or unfixing,

The slotted part of the bar at the bottom goes too much, the crank is adjusted to give the table a down between the shears, carrying the connecting stroke of about an inch more than the necessary rod pin. As the work bolted on the table occupies length of cut, for the purpose of clearance top and the same position as in turning, we do not require bottom, and to allow the feed being taken, when to interfere with the slide rest further than if the the table is at its highest and the tool disengaged stroke is more than the height of the centre, to lift from the work-and then by shifting the connectthe tool either by blocking up the slide-rest or by ing pin, K, we can make the table occupy the exact using the cranked tool-holder (Fig. 4). position wanted in relation to the tool. It is immaterial which way the fly-wheel is driven, but if the adjustable crank is screwed on to its small shaft, turning the wheel backwards will prevent it unscrewing.

Driving Gear. In a line almost with the front of the head-stock a stout upright standard, E, Fig. 3, is fixed, the top being fastened to the back of shears, this thy but bolts is a frame, F, carrying a toothed and the bottom resting on the floor. Attached to wheel and a crank with adjustable throw, G and H. On the lathe crank shaft is keyed fast a pinion, I, which gears into this wheel, their proportion being about four to one. This I found by experiment to be the best working speed for a 6in. stroke. In driving, the lathe-band is off, the head being idle, the pinion on crank shaft-gears with toothed wheel in frame, which carries round crank, H, communicating its motion to table through connecting rod, J. It is a remarkably easy pleasant motion. taking a good cut without lagging in its speed the least.

To make the working plain we will take a slide such as this (Fig. 5) and plane it. It will require to be gripped three times-viz., to plane the bottom, the top, and the ends-the V.'s must be planed with the top and the square sides-although it seems indifferent whether we plane them with the top or the bottom-will be better planed at the same sitting as the V.'s, as we will then be sure to get them parallel.*

I am a worker in brass, and I dare say biassed in favour of it for work such as this: gun-metal, or, I should say, hard bush-metal, the composition used

and all with the least possible disturbance of the
lathe.
Screwed up right against front of head-stock,
standing upon the shears, is the bed, Fig. 1, a box-
shaped casting 14in. high by 8in. wide. The mandrel
nose projects through it, and at the back a saddle,
with two bolts, screwing into two projecting pieces,
A, on the bed the thickness of the head, clasps
both firmly together; these pieces, A, with two
pieces at the bottom, B, being fitted to head to pre-
vent shake, and a binding-down bolt, C, Fig. 3,
from the bottom through the shears, completes the
fastering.

The table, Fig. 2, 11in. square and in. thick, slides on the bed. It is drilled and tapped all over with in holes, and the face and the back bearings plased true to each other; on the back of it is screwed a stout flat iron rod, D, from the kole at the top of which a strong cord goes up and passes either over pulley on overhead, or over two pulleys screwed into roof, the end with a hook coming down at the back, on which is hung as much weight as almost counterbalances table and work.

But somewhere in the train, between the crank shaft
and table, we require to have some joint which will
act as our safety valve, seeing all our gear is rigid
as in taking the last cut into a corner or V, we are
apt to go a little too far, and when everything is
rigid as I had it at first, the weakest part gives,
which in my case was some of my pinion teeth, so
the toothed wheel is not now keyed to its shaft, but
a flange being keyed there, the wheel is slipped on,
resting against the flange, a large washer and a nut
screwing up the wheel tight enough to drive the
table, but not so tight as to prevent it turning if an

undue strain comes on it.

The two holes in the wheel-frame by which it is bolted to the standard are lengthened sufficiently to let the frame be lifted high enough, by slackening the bolts, to take the wheel out of gear, with the pinion when not in use, and a slot in the standard lets the back of the wheel pass right through it.

When we have got the work fastened to the table as low down as we can, to avoid elevating the tool

When first made it was driven off a slotted disc on mandrel nose, the mandrel being geared; but it was a By Mr. J. GILRAY, from the Journal of the Amateur roundabout way-the table went too fast, and it was very Mechanical Society. hard to drive.

for machine bushes, which has a little more tin in it, is in my opinion better than cast iron or even steel; it will not rust-it wears well-it taps wellcosts much less in the finishing, it can be set partially with the hammer and be soldered, and if spoilt or condemned for some other plan it is still worth, as old metal, at least half what you paid for it. Usually we get much better castings in brass than in cast iron, and, if careful, can make our patterns so that but a minimum of finishing is necessary. Now, this slide would be awkward to fix to our table as we have drawn it, but a careful workman, as well as making the pattern the shape of the article wanted, also bestows a thought on how it is to be finished, and makes provision for gripping it in his machine or lathe; very often, too, he even puts a piece on to grip it in the vice by. In the brass shop the square-holed chuck comes in for its full share of work, and the most of things an engneer would turn between centres in his lathe the brass-finisher gets a square tenon cast on to fit his chuck, and is thus able to turn off the whole article at once, cutting off the tenon as he takes it * In this case we could have chucked and turned the bottom quicker, usually, than it could be planed.